Nothing sweet about this debate

Amy Corderoy

It's the kind of vitriol usually reserved for climate science. But it's not the future of the planet that's at stake but the future of what we put in our mouths.

Last week, the ABC's television science program Catalyst claimed the causal link between saturated fat, cholesterol and heart disease was "the biggest myth in medical history". It followed up this week by describing cholesterol medications as toxic and potentially deadly.

After seeing the first episode, Australia's top medicine safety expert, Professor Emily Banks, urged the ABC not to air the follow-up, lest it unjustifiably encourage people to go off their anti-cholesterol medications, known as statins. "If people stop using their statins . . . it's very likely that it will result in death," she said.

Catalyst delved into a raging debate: has dietary guidance telling us to avoid fats pushed us towards more harmful sugar and carbohydrates instead?

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But the program also went a step further, arguing cholesterol was just an innocent bystander in the body's attempts to deal with the sugar-damage. It was not a big leap to claim statins were dangerous, and the research supporting them fraudulent.

Most experts in the field say there are huge holes in this thesis. Somehow, among the tribal online world, the debate has turned into one where you are either with the argument, or against it.

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But could both sugar and fat contribute to heart disease? The National Heart Foundation says excess sugar consumption causing problems does not rule out high cholesterol as a danger.

She says increasing sugar consumption is one of many changes in our diet, including increasing portion sizes, that have changed over her lifetime.

The National Prescribing Service says managing sugar intake is important, particularly for people at risk of both diabetes and heart disease. "But we certainly have a lot more evidence around the negative effects of higher than acceptable levels of cholesterol, I'm not sure there's such an evidence-base around blood sugar," manager of the service's MedicineWise phone line Sarah Spagnardi says.

She says cholesterol medications work by lowering the level of "bad", or LDL cholesterol, while increasing "good" HDL cholesterol. Trial after trial has found that doing so is likely to cut the number of plaques that form in the arteries and restrict blood flow.

Science writer Garry Taubes couldn't have said it better: "What you do in bad science is you ignore any evidence that's contrary to your beliefs, your hypothesis, and you only focus on the evidence that supports it," he told Catalyst.

Catalyst focused heavily on the opinions of US experts – one of whom believes vaccines can cause autism and another who promotes chiropractic and chelation for heart problems – while downplaying the conclusions of other expert groups.

The Cochrane Collaboration – the world's highest authority on medical evidence – published a review in January covering nearly 57,000 people, finding deaths, heart attack and stroke were all reduced among people taking statins.

Or there's the 2007 study in the Lancet, which pooled data from almost 900,000 people. It's finding? The lower the cholesterol, the fewer heart disease deaths.

The research referenced in Thursday's episode knowns as the "4S study" did not have its primary finding – "highly significant reductions in the risk of death and morbidity" – discussed.

University of Melbourne media ethicist Dr Denis Muller says it's important programs like Catalyst discuss areas of medical debate and controversy. "But there is a duty on the reporter to be fair about the quality of the science it's based on."

University of Sydney professor of pharmacy Andrew McLachlan, who has not conducted industry-funded research into statins, says he was concerned by what he saw as a lack of balance to allow viewers to make their minds up. "A reasonable person would never take a medicine that some 'experts' refer to as 'toxic'," he says. "This is strong and emotive language."

McLachlan says the weight of evidence shows cholesterol medications are effective and their benefits outweigh harms in people at moderate to high risk of heart disease.

The risks of side effects from the medication are real. Many users report muscle cramping, while the US Food and Drug Administration warns patients could experience impairments to thinking and memory and an increased risk of diabetes.

Little is known about how many Australians at low-risk of heart disease are inappropriately prescribed statins but evidence from the AusHEART study indicates it could be up to 30 per cent.

Head of the school of public health at the University of Sydney Professor Glenn Salkeld says part of the answer will lie in developing better decision aids where people can input their risk factors (such as weight) and preferences (such as not to take medication). In the end, he says people must also get the message that prevention is better than cure. "We pay a high price, many billions of dollars, for not heeding this advice. Some people will benefit from taking a prescription drug and others will not. All compelling reasons to . . . start exercising and switch to a diet rich in fruit, vegetables and healthy fats, like the Mediterranean diet."

NPS Medicines Line: 1300 633 424

The sugar thesis explained

Science writer Gary Taubes believes we have the diet story upside down. People who are fat either eat more, or exercise less. But what if their body's compulsion to store and hold fat is forcing them to eat more and stripping them of the energy for exercise? Sugar creates such a compulsion. It produces insulin, pushing fatty acids into fat cells and temporarily locking them there — removing a source of energy. Taubes says fat doesn't do that, yet the push to low-fat diets has shifted people from fat and towards sugar. He wants the traditional food pyramid turned on its head. Instead of being told to eat only small amounts of fat and large amounts of carbohydrate we should be told to do the reverse. But changing the advice would mean organisations such as the Heart Foundation admitting they have been wrong, as well as antagonising industry. How would the sugar industry cope if food producers tried to remove it from every processed product? Or the grains industry, if we were advised to abandon porridge, corn flakes and bread in the morning?